In hospitals and laboratories, tissue treating apparatuses, in each of which tissue specimens are automatically fixed, dehydrated, degreased, replaced and embedded in paraffin, are used for producing microscopic specimens of tissue specimens taken from living bodies.
For example, a conventional tissue treating apparatus is shown in FIG. 9. In the tissue treating apparatus shown in FIG. 9, a main body of the apparatus includes: a processing chamber 102 accommodating baskets 100, in which tissue specimens are contained; a plurality of liquid-chemical reservoirs 104a-104e being mounted on a rack 104 and storing liquid chemicals, with sequentially different concentrations, for performing an infiltration treatment of the tissue specimens in the baskets 100; and paraffin reservoirs 106a and 106b accommodated in a heat-retaining chamber 106. As to the liquid-chemical reservoirs 104a-104b, concentrations of the liquid chemicals in the liquid-chemical reservoirs 104a-104e are 104a<104b<104c<104d<104e (numbers of times of using the liquid chemicals are 104a>104b>104c>104d>104e).
Each of the liquid-chemical reservoirs 104a-104e and the paraffin reservoirs 106a and 106b is connected to a rotary valve 108 provided to the main body as a selection valve, and the rotary valve 108 is connected to the processing chamber 102 via an open/close valve 110.
With this structure, each of the liquid-chemical reservoirs 104a-104e and the paraffin reservoirs 106a and 106b is selectively connected to the processing chamber 102 by the rotary valve 108.
Further, inner pressure of the processing chamber 102 is increased and reduced by a pump 112, and the liquid chemical or paraffin can be supplied to the processing chamber 102 from one of the liquid-chemical reservoirs 104a-104e and the paraffin reservoirs 106a and 106b, which is selected by the rotary valve 108, in a state where the inner pressure of the processing chamber 12 is reduced.
The liquid chemical or paraffin, which has been supplied to the processing chamber 102 and brought into contact with the tissue specimens in the basket 100, is returned to the original reservoir by increasing the inner pressure of the processing chamber 102 by the pump 112.
Since the rotary valve 108, the open/close valve 110 and the pump 112 are controlled by a control unit 114, the tissue specimens are infiltrated in the given liquid chemicals and the paraffin according to a predetermined treatment sequence, which has been previously set in the control unit 114, and then the tissue specimens are infiltrated in the paraffin.
In the tissue treating apparatus shown in FIG. 9, the residual paraffin, which remains in the processing chamber 102 after completing the tissue specimen infiltration treatment, is cleaned by using a cleaning liquid stored in a cleaning-liquid reservoir 107 as described in Patent Document 1. Each of the liquid chemicals used for the infiltration treatment may be used as the cleaning liquid.
Patent Document 1: Japanese Laid-open Patent Publication No. 5-149846